Distributed Adaptive Coordinated Control for Enhancing Transient and Steady-State Performance in Airborne Hybrid AC/DC Electrical Power Systems

With the high penetration of renewable energy sources and the standalone operation characteristic for the airborne hybrid AC/DC electrical power system (HEPS) of more electric aircraft (MEA), the inertia has declined. This paper proposed a distributed adaptive coordinated control (DACC) strategy with bidirectional virtual inertia (VI) defense for resolving transient and steady-state problems of standalone HEPSs. The VI is introduced into the P_ac − f_ac and P_dc − v²_dc droops to mitigate the AC frequency and DC voltage square variations for individually enhancing their dynamic response, while the bidirectional VI defense between two subsystems is achieved through the power interaction of the paralleled interlinking converters (ICs). For ICs, the AC bus frequency and the DC bus voltage square can be uniformly controlled based on the normalization method, and the priority in the P_ac − f_ac and P_dc − v²_dc droops is determined by the proposed DACC, so that the ICs can preferentially support the side with more proportional critical loads, ensuring the optimal power quality of HEPSs. Meanwhile, the proposed DACC allows the power interaction on the ICs to be proportionally shared to prevent an excessively stressed IC and enables ICs to tolerate the maximum acceptable communication delay. With the distributed communication planned, the communication fault ride-through capability is activated. A small-signal model of the HEPS with the proposed control is established, and the overall stability analysis is verified by the dominant pole trajectory. Real-time hardware-inthe-loop tests demonstrate the effectiveness of the proposed control method.